diff --git a/source/extensions/filters/http/buffer/config.h b/source/extensions/filters/http/buffer/config.h
index afbf4ad8d226..e31cd5dbf75b 100644
--- a/source/extensions/filters/http/buffer/config.h
+++ b/source/extensions/filters/http/buffer/config.h
@@ -30,6 +30,8 @@ class BufferFilterFactory
       Server::Configuration::ServerFactoryContext&, ProtobufMessage::ValidationVisitor&) override;
 };
 
+DECLARE_FACTORY(BufferFilterFactory);
+
 } // namespace BufferFilter
 } // namespace HttpFilters
 } // namespace Extensions